We have just learned some useful methods, that will help us manipulate objects and arrays. In this exercise, we will practice working with these methods, and you are required to use at least one of them in each iteration.
- Fork this repo.
- Clone this repo.
- Practice JavaScript advanced methods (
map,reduce,filterandsortto manipulate arrays).
- Upon completion, run the following commands:
$ git add .
$ git commit -m "Solved lab"
$ git push origin master- Create a Pull Request so that your TAs can check your work.
This LAB is equipped with unit tests to provide automated feedback on your lab progress. In case you want to check the tests, they are in the tests/movies.spec.js file.
To run the tests and your JavaScript code, open the SpecRunner.html file using the Live Server VSCode extension.
To see the outputs of the console.log in your JavaScript code, open the Console in the Developer Tools.
You will work on the src/movies.js file, which is already loaded in the SpecRunner.html file.
The src/data.js file containing the array of movies is also loaded in the SpecRunner.html file.
The best way to practice is to work with real data. In the src/data.js file, you will find an array of info about the best 250 movies of all times according to IMDB Ranking that you will use to display what each iteration asks!
Here is an example of how the data is displayed:
{
"title":"The Shawshank Redemption",
"year":1994,
"director":"Frank Darabont",
"duration":"2h 22min",
"genre":["Crime","Drama"],
"score":9.3
}You will be digging deeper into some "facts" that this data set has. For example, we can use this data set to find which is the most popular movie, what is the average duration of the movie, the list of movies by some director, etc.
In this iteration, no action is required, but here comes your challenge: In the following iterations, you will use your JS knowledge to manipulate this data.
Remember to read each iteration description carefully before working on the solution.
We need to get the array of all directors. Since this is a warm up, we will give you a hint: you have to map through the array of movies and get all the directors into one array as a final result. Go ahead and create a function named getAllDirectors() that receives an array of movies as an argument and returns a new (mapped) array.
It seems some of the directors had directed multiple movies so they will pop up multiple times in the array of directors. How could you "clean" a bit this array and make it unified (meaning, without duplicates)? Don't prioritize the bonus part now, you can come back to it when you are done with the mandatory iterations. 😉
One of the most famous directors in cinema is Steven Spielberg, and he has some really awesome drama movies that are on our list, but we want to know how many of them are there.
Go ahead and create a howManyMovies() function that receives an array as a parameter and filter 👀 the array so we can have only the drama movies where Steven Spielberg is the director.
These are the best movies based on their scores, so supposedly all of them have a remarkable score. In this iteration, we want to know the average score of all of them and display it on the console. Create a scoresAverage() function that receives an array as a parameter and solves the challenge.
The score must be returned rounded to 2 decimals!
💡 Maybe you want to "reduce" the data to a single value. 😉
Drama is the genre that repeats the most on our array. Apparently, people love drama! 👀
Create a dramaMoviesScore() function that receives an array as a parameter to get the average score of all drama movies! Let's see if it is better than the general average.
Again, rounded to 2 decimals!
We need to sort the movies in ascending order by their release year. This should be easy using one of the methods we have just learned. 😉
Create a function orderByYear() that receives an array as parameter and returns a new sorted array.
If two movies have the same year, order them in alphabetical order by their title! ✔️
Another popular way to order the movies is to sort them alphabetically using the title key. However, in this case, we only need to print the title of the first 20. Easy peasy for an expert like you. 😉
Create a orderAlphabetically() function, that receives an array and returns an array of first 20 titles, alphabetically ordered. Return only the title of each movie, and if the array you receive has less than 20 movies, return all of them.
We get the info from the IMDB web page, but the duration info was saved in a format that difficult us a lot to compare movies.
Finding the longest movie is almost impossible using that format, so let's change it!
- Create a
turnHoursToMinutes()function that receives an array as parameter, and with some magic implemented by you - replaces the duration info of each of the movies for its equivalent in minutes. For example:
{
"title":"The Shawshank Redemption",
"year":1994,
"director":"Frank Darabont",
"duration":"2h 22min",
"genre":["Crime","Drama"],
"score":9.3
}Should be:
{
"title": "The Shawshank Redemption",
"year": 1994,
"director": "Frank Darabont",
"duration": 142,
"genre": ["Crime","Drama"],
"score": 9.3
}We always hear so much about classic movies, but we want to know which year has the best average score, so we can declare the BEST YEAR FOR CINEMA officially!
Go ahead and find which year have the best average score for the movies that were released on that year!
Create bestYearAvg() function that receives an array of movies and gives us an answer which year was the best year for cinema and what was its average score. The bestYearAvg() should return a string with the following structure:
The best year was <YEAR> with an average score of <RATE>
Happy coding! 💙